Whenever programming originates from outside of the studio, or if listeners/viewers are calling up a phone-in using telephone hybrids or codecs, mix-minus feeds are required. Most telephone lines incur delays which prohibit off-air monitoring, because the caller, or remote talent, would hear their own voice in delay which is very disconcerting. The solution is to feed a mix back to the caller minus his or her own voice. Some mixing desks do not have a dedicated telco channel to generate a clean-feed, or mix minus, so the RB-MM1 can be used. The RB-MM1 is a unit for generating a suitable mix to send to a telephone hybrid or codec. A stereo output is taken from a mixer, together with a post fader output from the mono telephone fader on the mixer. The caller audio is removed from the station output so that it can be sent to the telephone line via the hybrid.
Product Features
Simple clean feed / mix minus generation.
Neutrik XLR-3 balanced line connections.
Output level adjustment.
Cancellation null adjustment.
Band pass filter.
Typical Applications
Used with mixers without mix-minus buses.
Product Category
Telephone Mix Minus Generators
Technical Specifications
Audio Specification
Maximum Input Level: +28dBu
Input Impedance: >20kΩ
Maximum Output Level: +28dBu
Output Impedance: <50Ω
Output Gain Range: Adjustable -15dB to +12dB, ref 0dBu gain via a multi-turn pot
Common Mode Rejection: >60dB
Band Pass Filter Range: 200Hz to 4kHz, 12dB/octave
